Lack of seasonal variation of symptoms in patients with Chronic Fatigue Syndrome (CFS)

Several of the symptoms involved in chronic fatigue syndrome
(CFS) such as fatigue, hypersomnia, hyperphagia, weight gain,
and mood show seasonal variations in the general population.

The aim of this study was to investigate whether patients with
CFS experience seasonal fluctuations in these symptoms as
well. Seasonal variation of symptoms was assessed in a group
of 41 patients with CFS and 41 controls closely matched for
age, gender, and city of residence. Participants were
recruited across the US and were asked to complete the
Seasonal Pattern Assessment Questionnaire (SPAQ) and the
Profile of Mood States (POMS). CFS patients showed
significantly lower scores on multiple SPAQ-derived measures
as compared with controls. These included seasonal variation
in energy, mood, appetite, weight, and sleep length. Patients
also reported a significantly reduced sensitivity toward
sunny, dry, and long days than controls. No association was
noted between intensity of seasonal changes and severity of
depressive symptoms. Patients with CFS exhibit an abnormally
reduced seasonal variation in mood and behavior and would not
be expected to benefit from light therapy.